Pathogenic Microorganisms

Pathogenic Microbes

The bad news is that soil contamination has the longest, most persistent potential for harboring a pathogen. The good news is beneficial bacteria and fungus compete for food and space. These good guys form protective nets/webs around roots and leaf surfaces all the while producing vitamins and antibodies that lay to waste the microbes living off of a healthy plant. This prevents most pathogenic bacteria and fungus from invading a plant, be it roots stems or leaves. Soils with a high diversity of bacteria and fungal types are more likely to have a larger number of non-pathogenic microbes. These beneficial microbes will out-compete their pathogenic cousins. Using the soils own food web's natural defenses is by far the better way to keep the bad guys at bay. You might want to check out the report I put together Bacterial Biofilms. It's amazing the energy, both chemical and ethereal, that is directed at the bacterial level pushing to form communal colonies of biofilms. Personally, I like clean sheets at home but these little guys think their slimy adobes are to-die-for.

Broad Mites are a very real hazard when propagating peppers. Of all the foods available for them to eat, peppers are the most nutritional for this pest. So heads-up. If you are going to grow your own supply of super hot capsicum like the Bhut Jolokia Ghost Pepper, or even the simplest sweet baby bell, you need to know how to identify and control this big problem this little bug can cause. Way back when I first started growing pepper plants, my peppers caught this bug instantaneously. I am growing in the upper central valley in my beautiful home nest of Costa Rica. I searched the internet images for the deformations and dried up initiating flowers I was experiencing. I found what I was looking for immediately. I was convinced the deformations were viral orientated. I was wrong. It wasn’t until I brought in an infected pepper plant to Lisela Moreira and Mauricio Montero Astuaat at the Centro de Investigación en Biología Celular y Molecular (CIBCM) of the Universidad de Costa Rica. They identified the culprit. I now know what was effecting my precious peppers so badly. Broad Mite Polyphagotarsonemus latus Polyphagotarsonemus latus was getting its Capsaicin from my peppers. P. latus is not visible with the naked eye. If you are very astute you ‘may’ be able to see it with the help of a magnifying glass. It is a minute herbivorous insect that infests a wide variety of plant crops including Solanaceae and Cucurbitaceae. This tiny mite causes severe symptoms and yield losses. Its destruction is mostly confined to new growths. The resulting damage is the curling of leaf margins, firmness of new leaves, necrosis of growing points, aborted buds, malformed fruits and growth inhibition.(1) Broad Mites mostly feed on the underside of tender young foliage and floral structures such as flower buds. This retards growth and prevents flowers from fully developing. Leaf damage includes bronzing and distorted, the downward curling of leaves resulting from a phytotoxin secreted by feeding mites. This toxin phytotoxin is still present even after the mite has been eliminated. So mite damage is a very serious problem In peppers, young damaged leaves in the growing point curl up on the edge. Severely infested plants become stunted and may eventually die. Broad mites can be dispersed within a greenhouse by attaching themselves to whiteflies, greenhouse workers or equipment, or by movement of infested plant material into and throughout the greenhouse. Life Cycle of the Broad Mite The life cycle of P. latus passes through egg, larva, quiescent nymph and adult stages.(2) Copulation occurs immediately after the female has emerged from the quiescent nymph skin. Mated females produce both males and females, while unmated females produce only males. Eggs are laid singly on the underside of leaves often near the veins and depressions. The eggs will then hatch in 2 to 4 days . The larva becomes a protonymphs in about another 2 days. The protonymph, after under going a quiescent stage, develops into a deutonymph. At this stage sexes are determined. The deutonymph stage lasts for 1 to 3 days more. Next, the mite transforms itself into a quiescent pupal stage which sticks to the under side of the pepper leaves. The pupal stage lasts for about 2 days. Male longevity is 9-13 days and females live for 14-20 days. Bilogical Control of Polyphagotarsonemus latus Biological Control studies by the Zoology Department, Faculty of Science, Ain Shams University in Egypt evaluated seven pesticides against different stages of P. latus infesting pepper. Their studies included the use of Abamectin (Vertemic 1.8% EC) (40 cm/100 L water), Liquid sulfur...

“I Have Whiteflys!!!” From one morning to the next you mossy over to your pet bushes and bend down to smell one of your favorites. Like a bad dream, you see a white flex fleeting the vicinity of your incoming nostril breath. An old wound in your soul opens as you realize, “there back!”. Immediately you run to the microbe biological medicine cabinet in the garden house’s refrigerator. There you frantically search for the right bacteria, or was it fungus. A cold sweet breaks out on your forehead as you fumble for your list and notes. It reads: Trichoderma asperellum Beauveria B. Orthezia Metarrhizium Isaria fumosorosea Paecilomyces lilacinus Bacillus subtilis Streptomyces griseoviridi Pseudomonas fluorescens Rhizobium Cladosporium herbarum Bacillus thurigiensis var israelensis Lecanicillium spp Biological Control Biological control is a very effective method. There are two microbial fungus that will place the persistent adult whitefly on on his knees. They are Isaria fumosorosea and two Lecanicillium spp, L. lecanii and L. muscarium. There is also a fungus named Paecilomyces lilacinus that can destroy the young in the nymphal stage. A mix of the four I use as a preventative if I have had a prior attack. For a preventative, give your plants a light spraying every month and you should be good. Once infested, make a strong concentration of the fungus spores and give the plants a thick spraying. Spray in the morning when the flies are just getting up. It’s still cool at that time and they will more or less stay put as you apply the fungal predators. You are spraying fungal spores, so it will take a few days for them to pop and grow hyphae. Spray every 3 or four days until the fly population decreases and you notice a light white fungus on some leaves. This will be between 10 and 15 days. Six WhiteFly Stages: egg 1st nymphal stage (crawls) 2nd nymphal stage (stationary) 3rd nymphal stage pupal adult About Whiteflys Whiteflies are closely related to aphids, mealybugs and scale, all of which feed by sucking sap from plants. Whiteflies can be found on the undersides of leaves and are active during the daytime when the temperature is warm. Whiteflies damage plants by sucking out plant juices. Large amounts of sap are removed by the developing nymphs, seriously weakening them. Leaves often turn yellow, appear dry and drop prematurely. If that doesn’t sound bad enough, whiteflies suck out more plant juice than they can digest. They excrete the excess sweet, sticky substance referred to as honeydew. The honeydew covers leaf surfaces and acts as a growth medium for a black, sooty mold. If left to live, the adult whitefly’s lifespan is roughly 40 days depending on temperature, plant, and fly species. Egg Stages Whiteflies deposit eggs on the underside of plants leaves. Adult females usually lay between 200 and 400 eggs. Though individually the eggs are almost non-detectable to the naked eye. But upon close inspection you can see the small whites of their ova. The whitefly many times lays her eggs in circle groupings, because the female will often keep her mouth feeding on the plant to feed while rotating in a circle. Normally the eggs are surrounded by their characteristic white, powdery film, making them easier to see. Unfertilized eggs will become male, fertilized eggs will become female. After the eggs hatch, begins the 3 nymph stages called instars. Nymphal Instar Stages The 1st instar stage is the crawling stage, wondering about the plant. Soon, he will insert his mouthparts into the plant and begin to feed. After his 1st molt, the crawler loses...

Phytophthora is a genus of plant-destroying Oomycetes, commonly called water molds. Approximately 100 species have been described, although 100-500 undiscovered Phytophthora species are estimated to exist. I just hope one doesn’t invade my hydro-organic system. But I doubt it will. If you have a strong growth of beneficial biofilm going in your system, you most probably will never encounter this most common hydroponic fungus-like pathogen. Phytophthora is morphologically very similar to true fungi yet its evolutionary history is quite distinct. In contrast to fungi, they are more closely related to plants than animals. Phytophthora species are well adapted to the diverse environments that they encounter in different seasons and environments. They produce several types of structures. Some ensure survival in the absence of a host plant. Others are well suited for infecting plants or dispersing to other plants. All the structures are so small that a microscope is necessary to see...

Fungus Gnats or Root Gnats are two common names for a few flying insects Diptera Mycetophilidae, Lycoriella spp. or Bradysia spp. These are arthropods that might be a nuisance flying around haphazardly knocking into leaves and the sides of your pots. I use organic substrates and I hate those critters. Growers using traditional hydroponic (using no substrate inoculates) see them a lot less. The adult fly is feasting on small pieces of organic matter breaking it down for even smaller organisms to mineralize. I hate gnats because once they have moved in, they are hard to move out. The adults are in-your-face but upon closer inspection you will find their larvae in the first few centimeters of your substrate. The larvae are so small you can barely see them with the naked eye. They feed on fungus for their livelihood. They also can get aggressive and do damage to some small root hairs as well. It’s a dog eat dog, arthropod eat fungus world down their. Just be thankful your not part of the food chain. Identifying Fungus Gnats Fungus Gnats are darker and appear delicate, similar in appearance to small mosquitoes. You will first see the adults scampering around bottom leaves, the surface of the soil or the edge of your container. Females lay small, unnoticeable eggs in moist, organic potting soil. The adults are weak fliers often stumbling up on a leaf’s surface. If the adults are present you can count on having the larva down under, perhaps even eating your tips. The small squares in the image of gnat larvae to the right, are one mm square. Controlling Fungus Gnats Organically Prevention is the best method for the control of pesky pests Inoculate the substrate with Bacillus thuringiensis Place a barrier of some sort Reenforce the barrier with an organic deterrent Once infested place sticky glue on surfaces Ten days latter… NO more gnats! Controlling Fungus Gnats Organically, believe it or not, is a snap! For prevention I put a bacteria to work right away upon planting. It takes a while after any microbial inoculation for the microbes to dig-in and reproduce, so upon planting, before gnats appear, is a good time to inoculate. The biological predator Bacillus thuringiensis subspecies israelensis, commonly called BTI is toxic to the larvae. Researchers investigated how this bacteria kills particular insects and discovered that BTI has two classes of toxins; cytolysins (Cyt) and crystal delta-endotoxins (Cyt)[1]. Cyt proteins are toxic towards Diptera. As a toxic mechanism, Cyt proteins bind to specific receptors on the membranes of mid-gut cells resulting in rupture of those cells[2]. Another preventative, of which I highly recommend, is to discourage the adult fungus gnats from laying eggs with a barrier to its nesting grounds, the substrate. I have seen people place a half centimeter layer of clean sand on the substrates surface. However, I place a solid poly-barrier between the riotous mob and our organic substrate. The CO2 from the roots metabolism can escape but there are few holes a gnat can enter.It’s easy and an inherent part of our system. Around the hole from which the plant stem protrudes from, place a deterrent like neem oil or/and pyrethrins. These will not decay and create more fungus food for the fungus gnats to eat. I was told there are two types of hot peppers. One is very hot, the other BURNS. I use the one that burns like fire, but the gnats barely noticed. Two days later the accumulation of a few spraying of hot pepper must of produced fungus. It was being eaten by the...

Equations and Symbols

Get Up-to-Speed on Microorganisms

Soluable Salt Ranges

Keeping up on your soluble salt range is important. Always have an instrument at hand to check your nutrient levels. The below chart is a general guide as to what levels are acceptable or not.

Desireable

Permisable

Dangerous

EC

.75-2 mS

2-3 mS

3 mS & ↑

PPM

500-1300

1300-2000

2000 & ↑

Electrical Conductivity (EC) of a solution is a measure of ionic compounds dissolved in water. Organic Nutrients are ionic compounds. Another name for ionic compounds is salts. Assuming the water had very little EC before you added the liquid fertilizer, measuring the EC will tell us how much fertilizer we have in our liquid. EC is commonly measured in milli-siemens (mS) and/or Total Dissolved Solids (TDS) expressed in Parts Per Million (PPM). Both will give you the same information of how much fertilizer is in your liquid. The EC and PPM are always in relation. So stating the EC and PPM is redundant. The relationship is 1 EC (measured in mS) = 650 PPM.

About BioChar Pyrolysis

Quote from:
Daniel D. Warnock & Johannes Lehmann & Thomas W. Kuyper & Matthias C. Rillig
"Biochar is a term reserved for the plant biomass derived
materials contained within the black carbon
(BC) continuum. This definition includes chars and
charcoal, and excludes fossil fuel products or geogenic
carbon (Lehmann et al. 2006). Materials
forming the BC continuum are produced by partially
combusting (charring) carbonaceous source materials,
e.g. plant tissues (Schmidt and Noack 2000; Preston
and Schmidt 2006; Knicker 2007), and have both
natural as well as anthropogenic sources. Restricting the oxygen supply during combustion can prevent complete combustion (e.g., carbon volatilization and
ash production) of the source materials. When plant
tissues are used as raw materials for biochar production,
heat produced during combustion volatilizes a
significant portion of the hydrogen and oxygen, along
with some of the carbon contained within the plant’s
tissues (Antal and Gronli 2003; Preston and Schmidt
2006).... Depending on the temperatures
reached during combustion and the species identity
of the source material, a biochar’s chemical and
physical properties may vary (Keech et al. 2005;
Gundale and DeLuca 2006). For example, coniferous biochars generated at lower temperatures, e.g. 350°C, can contain larger amounts of available nutrients,
while having a smaller sorptive capacity for cations
than biochars generated at higher temperatures, e.g.
800°C (Gundale and DeLuca 2006). Furthermore,
plant species with many large diameter cells in their
stem tissues can lead to greater quantities of macropores
in biochar particles. Larger numbers of macropores
can for example enhance the ability of biochar
to adsorb larger molecules such as phenolic compounds
(Keech et al. 2005)."
Check out the entire report at:
Mycorrhizal Responses to Biochar in Soil–Concepts and Mechanisms"

Biochar & Fungi Relationship

Cation Exchange Capacity Information Blurb

The total CEC is impacted by these factors:
Amount of active humus such as compost, Amount of passive humus such as Biochar, The pyrolysis method of the Biochar added, Was the Biochar activated and/or inoculated? The type and amount of microorganisms, and The overall pH